Chain-tightener



10 MODEL;

F. J AGKSON.

CHAIN TIGHTENBR. APPLICATION PILE D l f A R. 4, 1903 PATBNTED FEB. 1 1904;

U ITED ST-urns" Patented February 16, 1904.

PAT NT OFFICE.

FRANK JACKSON, or D NVER; COLORADO.

' cHAImTIG T-ENER.

srnorrrcn'rxon forming part of Letters Patent No. 752,074, dated February 16, 1904.

Application filed March 4, 1903. serial H0. 146,088.- (in model.)

To all whom it may concern:

Be it known that I, FRANK Jackson, a citizen of the United States of America, residing in the city and county of Denver and State of Colorado, have invented certain-new and useful Improvements in Chain-Tighteners; and I do declare the following to be a full, clear, and

exact description of the invention, such as will enable others skilled in the art to which it ap-- pertains to make and use the same, reference being bad to the accompanying drawings, and

to the figures of reference marked thereon, which form a part of this specification.

,My invention relates to improvements in ad justable chain-tighteners.

The object of the invention is to provide an implement of this character which is designed to be employed in repairing the driving-chains of automobiles and bicycles and sprocketchains wherever employed without the necessity of removing the chain from the vehicle or machine, the tightener holding the chain taut,

so that the links between the engaging-jaws of the said tightener will be slack and may be removed for the purpose of repairing or for the purpose of replacing them with new links.

A further object of the invention is to provide a clamping-nut for the tightener which may be more quickly adjusted than the nuts in common use.

I attain these objects by the mechanism illustrated. in the accompanying drawings, in whicht Figure 1 is a perspective view of my improved chain-tightener. Fig. 2 is a side eleivation showing the application of the tightener, the clamping-nut thereof being in section. Fig. 3 is a sectional view of the clampmg-nut; and Fig. 4 is a sectional view of the nut, the same being shown upon a fragment of threaded rod and in position. to be moved 7 upon the rod without engaging the threads comprise the head portion, from opposite sides thereof.

Referring to the accompanying drawings,

the numerals 1 and 2 indicate the sliding jawheads, which are similar in construction and of which project jaws 3 and 4, which lie substantially at right angles to the head and are provided with hooked ,ends 5 and 6, respectively. The jaws 3 are broader and heavier than the opposite'jaws d ,and are employed when a chain having large links is to be repaired, 'while the jaws t are adapted for lighter-built chains, such as those used upon bicycles and light machinery. Each of the heads is provided with a pair of parallel holes- 7 which extend longitudinally through the same, and in the uppermost hole of the head 1 is rigidly secured in any suitable manner a rod 8 of a preferred length, which is threaded from near th head 1 to its free extremity. This rod is designed to pass loosely through the upper hole in head 2, and its free end receives a thumb-nut 9. A red 10 of suitable length is rigidly secured within the lower hole of head 2 and is designed to pass loosely through the corresponding hole in head 1.

Thus the two heads may be moved toward and away from each other, the rods serving as guides and also maintaining the heads in planes parallel to each other. This construc tion makes astrong and rigid implement, and the double slide-bearing of each head prevents any binding. I

My improved device operates as follows: When the chain 11 of a vehicle or machine is to be repaired or a new link inserted, the hooked jaws of the tightener are caused to engage the chain in the manner illustrated in paired or replaced will lie between the jaws.

' Each hooked jaw will engage either the. end

of a link or a link-bar connecting two links, according to the style of chain, and when the thumb-nut is turned thechainwill be drawn taut, so that the links lying between the jaws ployed in connection with the-tightenenl prefor to use-aspecially-constructed nut by which Fig. 2, so that the link or links to be re- IOO thuspermitting the said nut 11) be moved adjustments'can be more quickly made. This nut is constructed in the manner shown mostclearly in Fig. 3, wherein a portion, of the thr'ead'at each end of the nut and on opposite sides of the same isobliterated, as shown at 12. This may be accomplished by filing an ordinary nut or the nut may be so formed in the process of manufacture. These smooth portions are formed at an acute angle to the threaded bore of the nut and extend in from each end of the nut slightly beyond the longitudinal center of the threaded bore, thus leaving a slight space in the center of the bore which is unthreaded. vThe smooth portions taken together form a smooth or unthreaded bore which is slightly greater in diameter than the threaded bore and lies at an acute angle to the same. Thus when the nut is in its normal or horizontal position upon the threaded rod its threads will engage those of the rod and the nut may be manipulated in the usual manner; but when it is desired to unscrew the nut or to remove the same quickly from the rod the nut is shifted to" the position shown in Fig. 4:, when its threads will become disengaged from those'of the rod, which will then lie within the smooth bore of the nut,

along on or withdrawn from the rod.

My improved chain-tightener is strong,-

durable, and simple in construction and well I adapted to the uses for which it is intended. I do not wish, however, to be limited to the precise construction illustrated, as many In a chaintightei1er the combination of a pair of similarly-constructed jaw-heads, havlng jaws extending from their opposite side, each head having a pair of longitudinally-disposed holes which are parallel with each other; a threaded rod rigidly secured within one of the holes of one of saidheads, and passing bore, and which intersects the threaded bore at an acute angle, the pointof interseetion being unthreaded, substantially as described.

In testimony whereof I aflix mysignature in 5 presence of two witnesses.

' e f FRANK JACKSON. Witnesses: G. SARGENT ELLIo'rr, BESSIE Trionrrsou.

loosely through the corresponding hole in the 

